Electrophoresis migration tank having means for maintaining controlled conditions



Fel 27, 1968 A. J. LA PAGLIA STAI. 3,371,027

ELECTROPHORESIS MIGRATION TANK HAVING MEANS FOR MAINTAINING CONTROLLED CONDITIONS Filed April l. 1965 PRESET TEMP.' 22 @E coNTRoLLEn RESERVOIR HEAT EXCHANGER ANTHONY J. LdlPAGLiA ROYDEN N. RAND OTTO H. SAHMEL 3 y NVENTORS Buw-(Q AT TOR NEYS United States Patent O ELECTROPHORESIS MIGRATION TANK HAVING MEANS FOR MAINTAINING CONTROLLED CONDITIONS i Anthony J. LaPaglia, Greece, Royden N. Rand, Pittsford, and Otto H. Sahmel, Rochester, N.Y., assignors to Bausch d: Lomb Incorporated, Rochester, NX., a corporation of New York Filed Apr. 1, 1965, Ser. No. 444,615 7 Claims. (Cl. 21M- 299) This invention relates to electrophoresis and more particularly to a migration tank in an electrophoresis apparatus.

Electrophoresis is used in clinical analysis for separating the various fractions of proteins, enzymes etc. The accuracy of the process depends to a considerable extent on controlling of temperatures, humidity and pH `factor of the buffer solution during migration of the various fractions. Unless these conditions are controlled the readings do not give an accurate picture of the analysis. According to this invention it is intended to provide a migration tank which will provide a control of all conditions necessary to provide accurate readings in electrophoresis processes.

It is an object of this invention to provide an electrophoresis migration tank.

It is another object of this invention to provide temperature control through a heat exchanger, evaporation control within a substantially closed compartment, and providing a circuitous path for the electric current from the electrodes to the migration table.

It is a further object of this invention to provide an electrophoresis migration tank having means for maintaining controlled conditions for the migration process and an optical table surface to accommodate transmission of a wide wavelength range.

The objects of this invention are provided by a migration tank having two vbutter solution chambers for containing a buffer solution. A migration table extends between the two migration chambers at a level lower than the level of the perimeter of the tank. A cover is also provided to form a migration compartment which is substantially enclosed to control evaporation. The migration table is constructed with a winding passage immediately below the table surface to accommodate the flow of a temperature controlled fluid to maintain an even temperature in the migration compartment. The temperature controlled passages are defined by a conduit winding under the table surface between the two chambers with alternate spacing to permit positioning of an optical surface upon which the samples are deposited and the various fractions are migrated. The plate `forming the optical surface will transmit a wide range of wavelengths to permit scanning of the migrated sample for subsequently producing a readout signal.

The buffer solution chambers are for-med with a plurality of baiiles alternately extending from the lower and from the upper portion of the chamber to form a circuitous path for the electric current to -minimize the movement of the hydrogen and the hydroxide ions from the electrodes to the migration area.

The preferred embodiment of this invention is illustrated in the subsequent drawings and described in the following description. l

F IG. 1 is a plan view of the migration tank.

FIG. 2 is a cross section view taken on line 2--2 of FIG. 1.

FIG. 3 is a cross section view taken on line 3-3 of FIG. 1.

Referring to the drawings FIG. 1 illustrates the migration tank 1. The right hand portion of the tank defines a 3,371,027 Patented Feb. `27, 1968 buifer solution chamber 2 and the left hand portion of the tank defines a second buffer solution chamber 3. An electrode 4 extends into the chamber 2 and is connected to a source of electrical energy 5. An electrode 6 extends into the buffer solution chamber 3 and is connected to the opposite side of the source of electrical energy 5. A plurality of battles 7, 8, 9 and 10 extend vertically through the chamber 2 to 'form a -circuitous path between electrode 4 and the migration table 11. The same Construction of `baffles 12, 13, 14 and 15 are positioned to extend in a vertical manner in chamber 3. These bales have alternate passages on the top and bottom to cause the movement of ions to pass through this circuitous path. The specific manner of construction produces a circuitous path which aids in controlling the pH factor of the buifer solution included in the migration medium which extends across the surface 16 of the table 11.

A 'buffer solution is placed in the chambers 2 and 3 and is lled in the tank to a level just above the table surface 16. Agarose is added to the buffer solution in a small quantity to form a gelling agent. The thickness of the migration medium, which is the portion of the solution extending across the surface 16 of the table 11, of approximately 1.7 millimeters is adequate. The solution in the chambers 2 and 3 during the operation may be somewhat liquid in nature due to heating by the electric current, however, the migration medium on the table surface 16 is of a gelatin consistency which is semi-fluid to permit migration of the sample on the surface of the migration medium.

The upper edge of the perimeter of the tank 1 as shown lies generally in a horizontal plane at a level slightly higher than the surface 16 of the table 11. This will permit the pouring of the buffer solution containing agarose into the chambers to for-m an overflow thickness on the table surface 16. The circuitous path around the battles in the cha-mbers 2 and 3 will retard the movement of the hydroxyl and hydrogen ions from the electrodes to the migration area. This is necessary to control the pH factor of the migration medium on the table surface. The table 11 is preferably constructed `of quartz although other materials might be used which would provide light transmission through a wide wavelength range. This range must be from approximately 200 millimicrons and into the visible spectrum. The quartz plate 17 is ibonded to the tank intermediate the structure forming the two chambers 2 and 3. A passage 18 is formed in a conduit 19 bonded to the underside of the quartz Vplate 17 and intermediate the structure forming the buifer solution chambers 2 and 3. The conduit 19 rnay be a metallic substance or any material suitable for this type of a conduit. which will provide heat transfer from the quartz plate to the fluid in the conduit and also will provide a suitable bonding to the tank structure and the quartz plate. i

The conduit is connected to an inlet tube 20. The out let of the conduit is connected to the outlet tube 21. The inlet tube 20 and the outlet tube 211 are connected to each other through the reservoir 22, the heat exchanger 23 and the pump 24. The heat exchanger is provided with automatic temperature control with means to preset the fluid temperature at any desired temperature which provides the desired temperature of the migration medium on the quartz plate 17. The temperature of the migration medium is maintained by a continuous flow of fluid through the conduit 1S.

A cover 25 is positioned immediately above the migration table 11 to form a substantially enclosed compartment 26. The enclosed compartment 26 will maintain a substantially constant humidity. It is understood that the migration tank is enclosed within an apparatus which further assists in reducing movement of air across the surface of the migration medium.

The applicator 27 is positioned laterally across the migration tank l. The applicator consists of a bar forming a supporting structure positioned on each of the two lateral edges of the tank which carries a string applicator which engages the surface of the migration medium. The sample to be analyzed is positioned on the string and then applied to the surface of the migration medium at the points immediately above the optical surfaces 2.8.

The device will be described in the following paragraphs. The migration tank is lled with a solution consisting essentially of water, sodium or potassium phosphate, and agarose. This solution is poured into the chambers 2 and 3 to cause the chambers to fili and overflow across the surface 16 of the table il to form a thickness of a migration medium of approximately 1.7 mm. The migration medium which is the portion of the solution lying on the surface of the migration table will form a gelatinous like substance and permit migration of a sample which is then deposited into the medium.

A sample to be analyzed is positioned at various points on the length of the string 3@ which extends transversely under the bar 27. The specific points of each of the samples which are to be analyzed are placed on the string which will then be applied into the migration medium immediately above the optical surfaces of the quartz plate f1. The cover 25 is then positioned over the migration table 11 to form a substantially closed compartment 26.

The switch 31 is then closed placing an electrical potential across the terminals 4 and 6. The potential across erminals 4 and 6 generates an electric field across the migration table 1i. The electric field is maintained across the migration medium 32 on the migration table 11 for a predetermined length of time to cause the various fractions in the sample to migrate in accordance with their specific mobilities etc.

The bafiies in the chambers 2 and 3 are identical and provide a circuitous path for the ions formed on the electrodes 4 and 6 which move toward the migration table. The movement of the hydroxyl and the hydrogen ions to the migration medium is retarded to maintain a fairly constant pH factor on the migration medium. The chambers and baffles are identical so that ions which do pass through the circuitous path will tend to neutralize each other in the migration medium and therefore not materially change the pH factor of the migration medium.

When the desired migration has taken place the cover 25 is removed and the tank is positioned in a scanning apparatus in which a light is directed through the optical surfaces 28. The light will longitudinally scan the optical surface-s 28 and the absorption is recorded. Each of the surfaces will be scanned in sequence and a reading for each surface will then be recorded.

The preferred embodiment of this invention has been set forth in the above illustration and description and it is understood that other embodiments might be devised which would fall within the scope of this invention which is defined by the attached claims.

We claim:

1. An electrophoresis migration tank comprising, means defining two buffer solution chambers in spaced relation relative to each other, means defining a substantially horizontal migration table adapted to transmit radiation therethrough and having a migration surface intermediate said two chambers at a level lower than the upper edge of the perimeter of said tank, means for controlling the temperature of the mivration medium supported on the table surface, cover means enclosing at least the migration surface forming a compartment to control the humidity above the migration surface, an electrode in each of said chambers, and a plurality of bafiies constructed and arranged in a manner to provide a circuitous electrical path between the electrodes in said chambers and said migration table to thereby control the pH factor of the migration medium.

2. An electrophoresis tank comprising, means including electrodes defining two buffer solution chambers in spaced relation to each other, means defining a substantially horizontal table intermediate said two chambers and adapted to transmit radiation therethrough, a conduit engaging the under surface of said table and providing passage of a temperature controlled iiuid for regulating the temperature of the upper table surface supporting the migration medium, a cover positioned on said tank forming an enclosed humidity controlled compartment above the migration medium, a plurality of bafiies providing a circuitous electrical path between an electrode in each of said chambers and said migration table to coritrol movement in said chamber and pI-I factor of said medium, said conduit defining a plurality of paths laterally over said under surface and spaced so as to provide an optical surface for migration of samples on said migration table having light transmitting characteristics to facilitate light transmission through said table during -scanning of the migrated fractions on said optical surface.

3. An electrophoresis migration tank comprising, means defining two buffer solution chambers in spaced relation to each other, an electrode extending into each of said chambers, means defining a substantially horizontal migration table having a migration surface intermediate said two chambers, adapted to transmit radiation therethrough, at least one baffle in said chambers defining passage means intermediate each of said electrodes and said migration table, temperature control means providing passage of a fluid along one surface of said table to control the temperature of the migration medium supported on said table, a cover enclosing at least the migration surface and forming a substantially enclosed compartment to control humidity above the migration surface, thereby providing a temperature and humidity controlled electrophoresis tank.

4. An electrophoresis tank comprising, means defining a substantially horizontal table adapted to transmit radiation therethrough, means defining two extended passages yhaving one end adjoining the ends of said table, an electrode at the opposite ends of each of said passages, a conduit means engaging the under surface of said table providing passage means of a temperature controlled fiuid for controlling the temperature of a migration medium on the upper surface of said table, means enclosing said tank forming an enclosed humidity controlled compartment above the migration medium, said conduit defining at least one path over said under surface and spaced so as to provide at least one optical surface for vertical transmission of radiation through said migration table in areas of the table not engaged on the under side by said conduit means to thereby provide the temperature and humidity controlled tank.

5. An electrophoresis tank comprising, means including electrodes defining two buffer solution chambers in spaced relation to each other, means defining a substantially horizontal migration table intermediate said two chambers, baffie means in said chambers forming a circpitous electrical path from each electrode to said migration table to control pH factor of a migration medium on said table, a conduit engaging portions of the under surface of said migration table providing passage means of a temperature controlled fluid to control the temperature of the migration medium on said table, said table including a quartz plate for defining an optical surface for migrating samples on the migration medium, said conduit defining a plurality of paths laterally over said under surface and spaced so as to provide an optical surface over portions of said table not engaging said conduit, a cover enclosing at least migration table to thereby form an enclosed humidity controlled temperature regulated migration compartment.

6. An electrophoresis migration tank comprising, means defining a substantially horizontal migration table adapted for supporting a migration medium, means defining an extended passage means having one end of each of said passage means adjoining the ends of said migration table, an electrode in the opposite end of said passage means,

a conduit means engaging the under surfaces of the table providing passage means for a temperature controlled iiuid for controlling the temperature of the migration medium, aplate having the characteristic of transmitting a radiation bandwidth of 200 millimicrons of Wavelength to the visible spectrum forming a portion of said table, said conduit defining at least one path over said under surface so as to provide at least one optical area for supporting said migration medium, a cover enclosing at least the upper surface of said migration table to provide control of humidity in the migration compartment and thereby provide a temperature controlled migration compartment.

7. An electrophoresis tank comprising means including electrodes defining two buffer solution chambers in spaced relation to each other, means defining substantially horizontally migration table intermediate said chambers, conduit means engaging longitudinal portions of the under surface of said migration table and accommodating passage of a temperature controlled fluid to control the temperature of said table, means dening a light transmitting area intermediate the area of said table engaging said conduits to thereby provide a light transmitting surface for supporting migration of a sample on the migration medium, a cover positioned on said tank forming a humidity control-led compartment above the migration medium, at least one baie in each of said chambers defining an extended passage means intermediate each of said electrodes and said migration table to thereby control the pH factor of the migration medium on said migration table.

References Cited UNITED STATES PATENTS 2,888,392 5/ 1959 Grassmann et al. 204-299 Re.24,752 12/ 1959 Ressler 204-299 3,062,731 11/1962 Durrurn 2104-180 3,305,471 2/ 19617 Munchhausen et al. 204-299 3,317,418 5/1967 Zec 20A-180 HOWARD 'S. WILLIAMS, Primary Examiner.

E. ZAGARELLA, Assistant Examiner. 

1. AN ELECTROPHORESIS MIGRATION TANK COMPRISING, MEANS DIFINING TWO BUFFER SOLUTION CHAMBERS IN SPACED RELATION RELATIVE TO EACH OTHER, MEANS DEFINING A SUBSTANTALLY HORIZONTAL MIGRATION TABLE ADAPTED TO TRANSMIT RADIATION THERETHROUGH AND HAVING A MIGRATION SURFACE INTERMEDIATE SAID TWO CHAMBERS AT A LEVEL LOWER THAN THE UPPER EDGE OF THE PERIMETER OF SAID TANK, MEANS FOR CONTROLLING THE TEMPERATURE OF THE MIGRATION MEDIUM SUPPORTED ON THE TABLE SURFACE, COVER MEANS ENCLOSING AT LEAST THE MIGRATION SURFACE FORMING A COMPARTMENT TO CONTROL THE HUMIDITY ABOVE THE MIGRATION SURFACE, AN ELECTRODE IN EACH OF SAID CHAMBERS, AND A PLURALITY OF BAFFLES CONSTRUCTED AND ARRANGED IN A MANNER TO PROVIDE A CIRCUITOUS ELEC- 